Solar Milk Cooling with Insulated Milk Cans

The milk cooling solution developed by the University of Hohenheim is based on a commercially available DC Refrigerator equipped with an adaptive control unit for its conversion to a smart ice-maker that operates depending on the availability of solar energy. The ice-maker has a volume of 160l and is capable of producing approx. 8-13 kg ice per day. One system includes 25 reusable plastic blocks of 2 kg capacity and two 30l isolated milk cans with removable ice  compartment. To cool down 30l of milk from 36°C to 15°C in one of the supplied milk cans, the systems needs 6kg of ice and 90 minutes.

The smart ice-maker is powered by 600Wp solar PV modules together with two batteries with a total capacity of around 1.5Kwh. Thanks to the thermal energy storage, in form of the 25 2kg-Ice-blocks, the system is able to run autonomously for up to 7 days even during periods of low solar radiation and high ambient temperatures.